I like how it signs into Instantchess and seaches for an opponent in a single step. Graphics on the iPhone and iPad app are good but a little unconventional looking on the iPad app. Simple clean presentation with a quick and snappy interface. Dont like that I have to leave the app and go to settings to access the settings of the app. Hate the sounds but they can be turned off. A gong when you find an opponent and a clock ticking when your opponent moves. I find both extremely annoying.
When I first used this app I felt it was too simple and lacked features but the more I used it, the more I appreciated the simple elegance. Its now my favourite online chess app and I have tried them all. Oh, one more great thing...if you loose the connection or get a phone call mid game, it signs right back in again automatically and resumes the same game. None of the other programs do that.
Also, one innovation on the iPhone version is the crosshairs showing where your finger is when you move a piece. There have been a few different tricks tried in other chess apps to solve the problem of accurately moving that little piece with a fat finger on such a small screen and this ones seems to work the best.
Finally, I found it to have the least lag off all the other chess apps when used over 3G.
David C Ridge about Instant Chess, v2.6.8